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[SCSI] isci: atapi support

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Based on original implementation from Jiangbi Liu and Maciej Trela.

ATAPI transfers happen in two-to-three stages.  The two stage atapi
commands are those that include a dma data transfer.  The data transfer
portion of these operations is handled by the hardware packet-dma
acceleration.  The three-stage commands do not have a data transfer and
are handled without hardware assistance in raw frame mode.

stage1: transmit host-to-device fis to notify the device of an incoming
atapi cdb.  Upon reception of the pio-setup-fis repost the task_context
to perform the dma transfer of the cdb+data (go to stage3), or repost
the task_context to transmit the cdb as a raw frame (go to stage 2).

stage2: wait for hardware notification of the cdb transmission and then
go to stage 3.

stage3: wait for the arrival of the terminating device-to-host fis and
terminate the command.

To keep the implementation simple we only support ATAPI packet-dma
protocol (for commands with data) to avoid needing to handle the data
transfer manually (like we do for SATA-PIO).  This may affect
compatibility for a small number of devices (see
ATA_HORKAGE_ATAPI_MOD16_DMA).

If the data-transfer underruns, or encounters an error the
device-to-host fis is expected to arrive in the unsolicited frame queue
to pass to libata for disposition.  However, in the DONE_UNEXP_FIS (data
underrun) case it appears we need to craft a response.  In the
DONE_REG_ERR case we do receive the UF and propagate it to libsas.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams
2011-09-30 18:52:19 -07:00
committed by James Bottomley
parent 4f3f812dd3
commit b50102d3e9
6 changed files with 380 additions and 16 deletions
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24
drivers/scsi/isci/remote_device.c
View File

@@ -386,6 +386,18 @@ static bool is_remote_device_ready(struct isci_remote_device *idev)
}
}
/*
* called once the remote node context has transisitioned to a ready
* state (after suspending RX and/or TX due to early D2H fis)
*/
static void atapi_remote_device_resume_done(void *_dev)
{
struct isci_remote_device *idev = _dev;
struct isci_request *ireq = idev->working_request;
sci_change_state(&ireq->sm, SCI_REQ_COMPLETED);
}
enum sci_status sci_remote_device_event_handler(struct isci_remote_device *idev,
u32 event_code)
{
@@ -432,6 +444,16 @@ enum sci_status sci_remote_device_event_handler(struct isci_remote_device *idev,
if (status != SCI_SUCCESS)
return status;
if (state == SCI_STP_DEV_ATAPI_ERROR) {
/* For ATAPI error state resume the RNC right away. */
if (scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX ||
scu_get_event_type(event_code) == SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX) {
return sci_remote_node_context_resume(&idev->rnc,
atapi_remote_device_resume_done,
idev);
}
}
if (state == SCI_STP_DEV_IDLE) {
/* We pick up suspension events to handle specifically to this
@@ -625,6 +647,7 @@ enum sci_status sci_remote_device_complete_io(struct isci_host *ihost,
case SCI_STP_DEV_CMD:
case SCI_STP_DEV_NCQ:
case SCI_STP_DEV_NCQ_ERROR:
case SCI_STP_DEV_ATAPI_ERROR:
status = common_complete_io(iport, idev, ireq);
if (status != SCI_SUCCESS)
break;
@@ -1020,6 +1043,7 @@ static const struct sci_base_state sci_remote_device_state_table[] = {
[SCI_STP_DEV_NCQ_ERROR] = {
.enter_state = sci_stp_remote_device_ready_ncq_error_substate_enter,
},
[SCI_STP_DEV_ATAPI_ERROR] = { },
[SCI_STP_DEV_AWAIT_RESET] = { },
[SCI_SMP_DEV_IDLE] = {
.enter_state = sci_smp_remote_device_ready_idle_substate_enter,